A hardware description language (HDL) refers to a computer-language that facilitates the documentation, design, and manufacturing of a digital system, such as an integrated circuit. An HDL combines program verification techniques with expert system design methodologies. Using an HDL, for example, a user can design and specify an electronic circuit, describe the operation of the circuit, and create tests to verify operation of the circuit. In general, an HDL includes standard, text-based expressions of the spatial and temporal structure and behavior of the electronic system being modeled. HDL syntax and semantics include explicit notations for expressing concurrency. In contrast to most software programming languages, an HDL also includes an explicit notion of time, which is a primary attribute of a digital system.
An HDL simulator refers to a program that can simulate operation of a circuit design that is specified in an HDL. Simulated operation of the circuit design in this form facilitates design verification in which the user is able to compare the intended functionality of the circuit design with the HDL implementation of the circuit design.